BCD spectrophotometry of stars with the B[e] phenomenon I. Fundamental parameters

Low resolution spectra in the lambda lambda3.500-8600 Angstrom wavelength r ange of 23 stars with the B[e] phenomenon are presented. Spectral classific ation of 15 program stars was performed using the BCD spectrophotometric sy stem, based on tile study of the Balmer discontinuity, which is independent of interstellar and circumstellar dust extinctions and of circumstellar ga s emissions and/or absorptions. From calibrations of the (lambda (1), D) BC D parameters we determined the (T-eff, log g, M-bol) of the studied stars. For stars where this method could not be applied, we tried to estimate the temperature of the central star by using the Balmer and He I emission lines and/or their visible energy distribution. The colour temperature and the t emperatures obtained from the study of Balmer aid He I lines are consistent with each other. The new results are compared with those obtained previous ly by other authors and discussed for each star individually. For some star s. differences between the effective temperatures derived using the BCD cla ssification system and those obtained elsewhere, based on photometric or sp ectroscopic analysis. imply spectral-type classification disagreements rang ing from 2-3 up to 6 B sub-spectral types. The fundamental parameters of AS 119, CD-245 degrees 721, Hen2-91, HD 316375 and ED-11 degrees 4747 were de termined for the first time. A simple method was introduced to calculate to tal (interstellar-circumstellar) dust extinction towards the studied stars. For HD 53179, which is a double stellar system: and for HD 45677 and HD 50 138, which ar e suspected to be binaries: we predicted the characteristics of the components that are consistent with the observed (lambda (1), D) par ameters. However, the possible binarity of HD 45677 and HD 50138 still need s to be confirmed spectroscopically.